This invention relates to a novel physiologically active substance produced by a microorganism belonging to the genus Streptomyces, a process for preparing the same and a pharmaceutical composition containing the same.
As a result of studies of products of a large number of microorganisms obtained from nature with a view to providing useful novel physiologically active substances, it has been found that a physiologically active substance having a vasodilative activity was produced in the culture broth of a certain microcorganism. After isolation and purification of the substance from the culture broth, its physico-chemical properties have been investigated, whereby the substance has been found to be a novel physiologically active substance. The substance is hereinafter called "KS-619-1".
As for a vasodilator produced by a microorganism, WS-1228 A and B, which are produced by culturing a strain of Streptomyces aureofaciens and have the following chemical structures, have been known [J. Antibiotics 35, 151-156 (1982), ibid. 35, 157-163 (1982)]. ##STR1##